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Diffstat (limited to 'arch/arm/include/asm/uaccess.h')
-rw-r--r--arch/arm/include/asm/uaccess.h45
1 files changed, 39 insertions, 6 deletions
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 9556d04387f7..6c9c16d767cf 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -14,6 +14,8 @@
#include <asm/domain.h>
#include <asm/unaligned.h>
#include <asm/unified.h>
+#include <asm/pgtable.h>
+#include <asm/proc-fns.h>
#include <asm/compiler.h>
#include <asm/extable.h>
@@ -24,9 +26,10 @@
* perform such accesses (eg, via list poison values) which could then
* be exploited for priviledge escalation.
*/
+#if defined(CONFIG_CPU_SW_DOMAIN_PAN)
+
static __always_inline unsigned int uaccess_save_and_enable(void)
{
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
unsigned int old_domain = get_domain();
/* Set the current domain access to permit user accesses */
@@ -34,19 +37,49 @@ static __always_inline unsigned int uaccess_save_and_enable(void)
domain_val(DOMAIN_USER, DOMAIN_CLIENT));
return old_domain;
-#else
- return 0;
-#endif
}
static __always_inline void uaccess_restore(unsigned int flags)
{
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
/* Restore the user access mask */
set_domain(flags);
-#endif
}
+#elif defined(CONFIG_CPU_TTBR0_PAN)
+
+static __always_inline unsigned int uaccess_save_and_enable(void)
+{
+ unsigned int old_ttbcr = cpu_get_ttbcr();
+
+ /*
+ * Enable TTBR0 page table walks (T0SZ = 0, EDP0 = 0) and ASID from
+ * TTBR0 (A1 = 0).
+ */
+ cpu_set_ttbcr(old_ttbcr & ~(TTBCR_A1 | TTBCR_EPD0 | TTBCR_T0SZ_MASK));
+ isb();
+
+ return old_ttbcr;
+}
+
+static inline void uaccess_restore(unsigned int flags)
+{
+ cpu_set_ttbcr(flags);
+ isb();
+}
+
+#else
+
+static inline unsigned int uaccess_save_and_enable(void)
+{
+ return 0;
+}
+
+static inline void uaccess_restore(unsigned int flags)
+{
+}
+
+#endif
+
/*
* These two are intentionally not defined anywhere - if the kernel
* code generates any references to them, that's a bug.